Those familiar with subsea operations involving hydrocarbon recovery have recognized for decades that various subsea devices, such as control pods, must be powered by hydraulic or electrical lines extending to the devices from another location, such as the water surface. Since it may be necessary to repair or replace one such control pod, the hydraulic and/or electrical lines are coupled by suitable subsea connections. These connections accordingly are both made up and broken apart in the subsea environment, and those skilled in the art recognize the difficulty often encountered performing operations in a subsea environment which are relatively simple when performed in a normal atmospheric environment. Accordingly, the time and expense of utilizing a remotely operated vehicle (ROV) or a diver to perform the necessary coupling or decoupling operations can be significantly reduced if the coupling construction and method of coupling are simplified. Also, by increasing the reliability of the coupling operation, the risks associated with a more difficult and time consuming subsea operation is minimized. Accordingly, the overall costs associated with performing the subsea coupling and decoupling operations may be minimized by improved coupling technology.
ROV's traditionally have used to manipulate in position a junction plate assembly having either male or a female coupler halves, so that the moveable junction plate assembly may be secured to another plate assembly (e.g., a fixed junction plate assembly) having opposing male or female coupler halves to make up the coupled hydraulic or electrical lines. Traditionally, the movable junction plate assembly has a handle affixed thereto, which can be grasped by the arm of the ROV or diver for the purpose of manipulating the junction plate assembly to its desired position with respect to the fixed plate assembly. Once properly positioned, the ROV arm would then release the handle, and grasp a protruding drive screw of the junction plate assembly. The drive screw was subsequently rotated by the ROV to threadably connect the movable junction plate assembly to the fixed junction plate assembly. Those skilled in the art recognize that this sequence of operations, whether performed by a diver or an ROV, is somewhat cumbersome in the subsea environment. Problems have repeatedly occurred when trying to grasp either the junction plate handle or the protruding drive screw. Problems have also occurred when the movable junction plate assembly is not maintained in a secured position when the manipulating handle is released by the ROV, in which case the ROV arm may have difficulty grasping the protruding drive screw.
Additional problems are sometimes encountered when an ROV is moving a junction plate assembly from one location to another location. At times, the ROV may unintentionally release its grasp on the movable junction plate assembly, e.g., if the ROV is temporarily deactivated. When this occurs, the junction plate with the electrical and hydraulic lines connected thereto drops until it either rested on an object it strikes, or is suspended subsea from the electrical or hydraulic lines. In many cases, a falling junction plate assembly may drop to a position such that it is extremely difficult and thus costly to retrieve the junction plate assembly. Also, the dropping junction plate assembly may cause significant damage to either the junction plate assembly or to subsea components the assembly strikes, and/or may damage the hydraulic or electrical lines or their connections.
U.S. Pat. No. 4,194,857 discloses a subsea station with fluid conducting lines arranged to compensate for expansion and contraction, and to provide yieldability in the makeup connections. U.S. Pat. No. 4,611,831 discloses a connection device for connecting a series of circuits. A cylindrical lock is provided with a projecting head and a lateral pin. By compressing a biasing spring, the pin may be rotated 90 degrees to lock a first support piece to a centerpiece. The device of the '831 patent is not intended for subsea applications, and the cylindrical lock would not be easily adapted for securing a movable junction plate assembly to a fixed junction plate assembly in the reliable manner required by a subsea operators. U.S. Pat. No. 4,643,616 discloses a device for activating and connecting modules of a subsea oil production station. The device includes a telescopic articulated gib for manipulating a mechanical action connector. U.S. Pat. No. 4,915,419 discloses a locking mechanism for mating and unmating male and female coupling members in a subsea application. The apparatus includes a lock plate supported by a junction plate which is slidable between an unlocked position and a locked position. U.S. Pat. No. 5,024,467 discloses an assembly for coupling and uncoupling connection elements, such as pipes or conduits.
The disadvantages of the prior art are overcome by the present invention, and an improved movable junction plate assembly and fixed plate assembly for making up and breaking apart hydraulic or electrical couplings, and a method of connecting and disconnecting such couplings in a subsea environment, is hereinafter disclosed. The junction plate assemblies and techniques of the present invention have thus long been desired by subsea operators to meet the demands of systems which can reliably couple and uncouple hydraulic and electrical lines in subsea operations with minimal difficulty.